1. Field of the Invention
The present invention relates in general to the biotechnology field and, in particular, to an apparatus and method that can be used to effectively produce an array of transfected cells.
2. Description of Related Art
The recent completion of the Human Genome Project means that researchers are going to be asked to study the functions of thousands of known genes and unknown genes in DNA sequences. As such, the researchers are going to need tools that can enable them to effectively and expeditiously study the functions of these genes and the proteins encoded by these genes.
Traditional tools that are used by researchers to perform these studies are not effective, because they make it hard for the researchers to produce an array of transfected cells. The transfection of cells is the introduction of one or more of exogenous genes into target cells. Transfected cells produce the proteins encoded by the exogenous genes. The study of these proteins has diverse applications in a wide variety of fields including, for example, the pharmaceutical field, the medical field and the agricultural field. An example of a traditional cell transfection apparatus is briefly discussed below with respect to FIG. 1.
Referring to FIG. 1 (PRIOR ART), there is illustrated a perspective view of a traditional cell transfection apparatus 100. Basically, the traditional cell transfection apparatus 100 is a slide 102 on which a robotic arrayer prints a plasmid DNA 104 dissolved in an aqueous gelatin solution. The slide 102 is dried and the printed array of plasmid DNA 104 is covered with a lipid transfection reagent 106. Alternatively, the lipid transfection reagent 106 can be added to the plasmid DNA 104 before the DNA is printed. After removal of the lipid transfection reagent 106, the slide 102 is placed in a culture dish 108 and covered with cells in a growth media 110. The arrayed cells become transfected in one to two days after which the researchers can study the proteins encoded by the plasmid DNA 104. For a more detailed discussion about the traditional cell transfection apparatus 100 reference is made to an article by J. Ziauddin and D. M Sabatini, xe2x80x9cMicroarrays of Cells Expressing Defined cDNAsxe2x80x9d Nature 411, 107-110 (May 3, 2001). This article is hereby incorporated by reference herein.
Unfortunately, there are many drawbacks associated with the traditional cell transfection apparatus 100. First, the cells 110 attach and grow over the total surface area of the slide 102 covering the printed plasmid DNA 104 and the areas between the spots of plasmid DNA 104. As such, the transfected cells can be located only if transfection occurs and the plasmid DNA 104 is engineered to carry a marker or protein tag (e.g., green fluorescent protein, HA, FLAG), radiolabel or an antibiotic resistance protein. Secondly, the robotic arrayer prints the plasmid DNA 104 onto the slide 102 one spot at a time which is not only very time consuming but also slows down the production rate. Accordingly, there is a need for a cell transfection apparatus that is designed to address the aforementioned problems and other problems associated with the traditional cell transfection apparatus 100. This need and other needs are addressed by the cell transfection apparatus and methods of the present invention.
The present invention includes a cell transfection apparatus and methods for making and using the cell transfection apparatus. The cell transfection apparatus has a surface on which there is printed at different locations one or more foreign biomolecules (e.g., DNA, RNA, oligonucleotides, nucleotides). The foreign biomolecules can be printed at the same time. The surface is then covered with a transfection reagent which is incubated and removed from the surface before cells in a cell growth media are placed on the surface. The surface is configured such that the cells which become transfected with one or more foreign biomolecules are segregated from the cells which fail to become transfected with one or more foreign biomolecules. There are two embodiments of the cell transfection apparatus described herein.